Remove extra keys that are invalid in eslintrc (#358)

.neutrinorc.js

@@ -8,7 +8,6 @@ module.exports = {
         'packages/neutrino/bin/*'
       ],
       eslint: {
-        node: true,
         envs: ['browser', 'commonjs', 'node'],
         plugins: ['eslint-plugin-prettier'],
         rules: {

.travis.yml

@@ -19,5 +19,6 @@ install:
 before_script:
 - yarn bootstrap --frozen-lockfile
 script:
+- yarn validate:eslintrc
 - yarn lint
 - yarn test

package.json

@@ -8,6 +8,10 @@
   "bugs": "https://github.com/mozilla-neutrino/neutrino-dev/issues",
   "repository": "mozilla-neutrino/neutrino-dev",
   "scripts": {
+    "validate:eslintrc:root": "eslint --no-eslintrc --print-config . -c ./.eslintrc.js > /dev/null",
+    "validate:eslintrc:eslint": "eslint --no-eslintrc --print-config . -c ./packages/neutrino-middleware-eslint/eslintrc.js > /dev/null",
+    "validate:eslintrc:airbnb-base": "eslint --no-eslintrc --print-config . -c ./packages/neutrino-preset-airbnb-base/eslintrc.js > /dev/null",
+    "validate:eslintrc": "yarn validate:eslintrc:eslint && yarn validate:eslintrc:airbnb-base && yarn validate:eslintrc:root",
     "lint": "node packages/neutrino/bin/neutrino lint",
     "bootstrap": "oao bootstrap --no-parallel",
     "changelog": "changelog mozilla-neutrino/neutrino-dev all --markdown > CHANGELOG.md",
@@ -51,7 +55,11 @@
   },
   "lint-staged": {
     "*.js": [
-      "packages/neutrino/bin/neutrino lint --fix",
+      "yarn lint --fix",
+      "git add"
+    ],
+    "packages/neutrino/bin/neutrino": [
+      "yarn lint --fix",
       "git add"
     ]
   }

packages/neutrino-middleware-eslint/eslintrc.js

@@ -0,0 +1,6 @@
+const { Neutrino } = require('../neutrino');
+
+const api = Neutrino({ cwd: __dirname });
+
+// eslint-disable-next-line global-require
+module.exports = api.call('eslintrc', [require('.')]);

packages/neutrino-middleware-eslint/index.js

@@ -15,8 +15,13 @@ const reduceToTrueKeys = reduce((acc, key) => assoc(key, true, acc), {});
 const getEslintRcConfig = pipe(
   getEslintOptions,
   clone,
-  assoc('useEslintrc', true),
-  omit(['failOnError', 'emitWarning', 'emitError']),
+  // We remove these keys since they are needed when running the lint command but
+  // not the eslintrc command. The lint command uses ESLint's CLIEngine, but the
+  // ESLint RC format does not match the CLIEngine format exactly. We must remove
+  // anything we add that does not comply with ESLint's schemas.
+  // https://github.com/eslint/eslint/blob/9d1df92628dd4dd1e70fbb19454008e146387435/conf/config-schema.js
+  // https://github.com/eslint/eslint/blob/9d1df92628dd4dd1e70fbb19454008e146387435/lib/config/config-validator.js#L167
+  omit(['failOnError', 'emitWarning', 'emitError', 'cwd', 'useEslintrc', 'fix', 'extensions']),
   renameKeys({ envs: 'env', baseConfig: 'extends' }),
   evolve({
     extends: prop('extends'),

packages/neutrino-preset-airbnb-base/eslintrc.js

@@ -0,0 +1,6 @@
+const { Neutrino } = require('../neutrino');
+
+const api = Neutrino({ cwd: __dirname });
+
+// eslint-disable-next-line global-require
+module.exports = api.call('eslintrc', [require('.')]);